caretaker

caretaker
    n 1: a custodian who is hired to take care of something
         (property or a person)
    2: an official who performs the duties of an office temporarily;
       "he acted as a caretaker until a new president could be
       elected"
    

23 Moby Thesaurus words for "caretaker":
      air warden, attendant, castellan, conservator, curator, custodian,
      forest ranger, game warden, gamekeeper, governor, guardian,
      guardian angel, janitor, keeper, lifeguard, lifesaver, next friend,
      prochein ami, ranger, shepherd, steward, warden, warder